Materials For Biological Applications Research Articles

Miktoarm star polylactic acid/polybutylene succinate and its coherent characteristics

Miktoarm stars possess unique molecular architectures which each polymer chain expresses its physico-chemical properties either individually or integratedly. Up to present, although various biodegradable copolyesters, especially poly(lactic acid) (PLA) and poly(butylene succinate) (PBS), are known, the miktoarm star PLA/PBS is still not investigated. The present work proposes the application of arm-first approach to prepare core-crosslinked miktoarm star of poly(lactic acid) and poly(butylene succinate) (CCS-PLA/PBS). By simply polymerizing the bromo‑terminated macroinitiators with divinyl monomers, PLA and PBS chains are fixed at a central core to allow polymeric core-shell nanoparticle formation. As thermal properties of PLA and PBS are different, the variation of PLA/PBS ratio in CCS initiates thermo-responsive performances under glass transition temperature (Tg) and melting temperature (Tm) of PLA and PBS. The present work shows how the combination of two biodegradable polyesters as CCS introduces a new type of responsive nanoparticle which can be expected for advanced materials in biological applications.

High-Throughput Synthesis, Purification, and Application of Alkyne-Functionalized Discrete Oligomers.

The development of synthetic oligomers as discrete single molecular entities with accurate control over the number and nature of functional groups along the backbone has enabled a variety of new research opportunities. From fundamental studies of self-assembly in materials science to understanding efficacy and safety profiles in biology and pharmaceuticals, future directions are significantly impacted by the availability of discrete, multifunctional oligomers. However, the preparation of diverse libraries of discrete and stereospecific oligomers remains a significant challenge. We report a novel strategy for accelerating the synthesis and isolation of discrete oligomers in a high-throughput manner based on click chemistry and simplified bead-based purification. The resulting synthetic platform allows libraries of discrete polyether oligomers to be prepared and the impact of variables such as chain length, number, and nature of side chain functionalities and molecular dispersity on antibacterial behavior examined. Significantly, discrete oligomers were shown to exhibit enhanced activity with lower toxicity compared with traditional disperse samples. This work provides a practical and scalable methodology for nonexperts to prepare libraries of multifunctional discrete oligomers and demonstrates the advantages of discrete materials in biological applications.

NIR Mechanoluminescence from Cr3+ Activated Y3Al5O12 with Intense Zero Phonon line

AbstractMechanoluminescence (ML) materials with long‐wavelength emission bands are essential for future in vivo bioimaging, non‐destructive testing of solids, etc. The lack of a defined mechanism, however, prevents the application of near infrared ML materials above 650 nm in several new fields. Here, the addition of Ga3+ ions to Y3Al5O12: Cr3+ manipulates matrix microstructure evolution, boosting near‐infrared (NIR) zero‐phonon line (ZPL) stress optical output of the Cr3+ ion at 688 nm. The key factor changing the crystal field intensity Dq/B due to the addition of Ga3+ ions is what causes the luminescence amplification of ZPL. The ML fabricated by composite polydimethylsiloxane and Y3Al4GaO12: Cr3+ (YAGG: Cr3+) may penetrate chicken feet epidermal tissue and 4 mm pork tissue thanks to the strong NIR ZPL emission of YAGG: Cr3+ phosphor. This discovery of enhancing near‐infrared ZPL intensity by solid solution provides us with a new technique for optimizing NIR ML materials, as well as a new prospect for NIR ML materials in biological applications.

Piezo-Activated Atomic-Thin Molybdenum Disulfide/MXene Nanoenzyme for Integrated and Efficient Tumor Therapy via Ultrasound-Triggered Schottky Electric Field.

Monolayer molybdenum disulfide (MoS2 ) nanoenzymes exhibit a piezoelectric polarization, which generates reactive oxygen species to inactivate tumors under ultrasonic strain. However, its therapeutic efficiency is far away from satisfactory, due to stackable MoS2 , quenching of piezo-generated charges, and monotherapy. Herein, chitosan-exfoliated monolayer MoS2 (Ch-MS) is composited with atomic-thin MXene, Ti3 C2 (TC), to self-assemble a multimodal nanoplatform, Ti3 C2 -Chitosan-MoS2 (TC@Ch-MS), for tumor inactivation. TC@Ch-MS not only inherits piezoelectricity from monolayer MoS2 , but also maintains remarkable stability. Intrinsic metallic MXene combines with MoS2 to construct an interfacial Schottky heterojunction, facilitating the separation of electron-hole pairs and endowing TC@Ch-MS increase-sensitivity magnetic resonance imaging responding. Schottky interface also leads to peroxidase mimetics with excellent catalytic performance toward H2 O2 in the tumor microenvironment under mechanical vibration. TC@Ch-MS possesses the superior photothermal conversion efficiency than pristine TC under near-infrared ray illumination, attributed to its enhanced interlaminar conductivity. Meanwhile, TC@Ch-MS realizes optimized efficiency on tumor apoptosis with immunotherapy. Therefore, TC@Ch-MS achieves an integrated diagnosis and multimodal treatment nanoplatform, whereas the toxicity to normal tissue cells is negligible. This work may shed fresh light on optimizing the piezoelectric materials in biological applications, and also give prominence to the significance of intrinsic metallicity in MXene.

Chitosan-lactobionic acid-thioctic acid-modified hollow mesoporous silica composite loaded with carborane for boron neutron capture therapy of hepatocellular carcinoma

Nanocarriers have been recognized as an effective strategy for developing novel boron-containing delivery agents for boron neutron capture therapy (BNCT) of refractory tumors. Herein, a chitosan-lactobionic acid-thioctic acid-modified hollow mesoporous silica composite loaded with carborane was prepared to achieve effective treatment of hepatocellular carcinoma by BNCT. Notably, the composite remained stable under physiological conditions and exhibited high selective uptake in liver cancer cells. In the tumor microenvironment, the composite could effectively release carborane into the tumor tissue under the dual stimulation of pH and redox. The composite showed excellent efficacy in BNCT treatment of liver cancer cells. Meanwhile, the composite could exert antioxidant and anti-inflammatory effects to reduce the toxic side effects during BNCT. In tumor-bearing mice, the composite could accumulate in tumor tissue with high selectivity. In addition, the composite could be effectively cleared from the normal tissues and could overcome the inflammatory response generated in vivo by the materials in biological applications. Overall, the composite is a promising boron-containing delivery agent in the treatment of hepatocellular carcinoma by BNCT, and can facilitate the biological applications of the silica-like materials in BNCT.

Stimuli-Responsive Thiomorpholine Oxide-Derived Polymers with Tailored Hydrophilicity and Hemocompatible Properties.

Thermo-responsive hydrophilic polymers, including those showing tuneable lower critical solution temperature (LCST), represent a continuous subject of exploration for a variety of applications, but particularly in nanomedicine. Since biological pH changes can inform the organism about the presence of disequilibrium or diseases, the development of dual LCST/pH-responsive hydrophilic polymers with biological potential is an attractive subject in polymer science. Here, we present a novel polymer featuring LCST/pH double responsiveness. The monomer ethylthiomorpholine oxide methacrylate (THOXMA) can be polymerised via the RAFT process to obtain well-defined polymers. Copolymers with hydroxyethyl methacrylate (HEMA) were prepared, which allowed the tuning of the LCST behaviour of the polymers. Both, the LCST behaviour and pH responsiveness of hydrophilic PTHOXMA were tested by following the evolution of particle size by dynamic light scattering (DLS). In weak and strong alkaline conditions, cloud points ranged between 40–60 °C, while in acidic medium no LCST was found due to the protonation of the amine of the THOX moieties. Additional cytotoxicity assays confirmed a high biocompatibility of PTHOXMA and haemolysis and aggregation assays proved that the thiomorpholine oxide-derived polymers did not cause aggregation or lysis of red blood cells. These preliminary results bode well for the use of PTHOXMA as smart material in biological applications.

New Isolated Shrimp (Litopenaeus setiferus) Chitosan-Based Films Loaded with Fly Ash for Antibacterial Evaluation.

New three fabricated chitosan (CS) loaded with fly ash (FA) films were developed in this study. The shell waste of white shrimp was used as a precursor for the isolation of chitin and converted into chitosan by carrying out a deacetylation process. The formation of chitosan was conducted by various preparation steps deproteinization, demineralization, and deacetylation. The degree of deacetylation was found to be 95.2%. The obtained chitosan was used to prepare three different chitosan loaded-fly ash films. The prepared films contained various fly ash: chitosan ratios (2:1, FA-CSF1), (1:1, FA-CSF2), and (1:2, FA-CSF3). The obtained films were characterized using FTIR, XRD, and SEM. The micrograph images of the formed films showed spherical particles with an average size of 10 µm. The surface area, adsorption-desorption properties, thermal stability, and water/fat binding features of the fabricated chitosan films were studied. The results revealed that the prepared films displayed typical BET graphs with surface areas ranging from 2.436 m2 g−1 to 8.490 m2 g−1. The fabricated FA-CSF films also showed high thermal stability at temperatures up to 284.9 °C and excellent water/fat binding capacities. The antibacterial potential of the designed films was screened against E. coli (Gram-negative) and B. cereus (Gram-positive) bacterial strains. The tested solution of CS (1%) exhibited inhibition zones for E. coli and B. cereus as 18.51 mm and 14.81 mm, respectively, while in FA solution (1%), the inhibition zones were found to be 10.16 mm, and 13.57 mm, respectively. The results encourage and open up the new and promising areas of research for applying chitosan extracted from waste materials in biological applications.

Black Phosphorus in Biological Applications: Evolutionary Journey from Monoelemental Materials to Composite Materials

ConspectusUnderstanding the evolutionary journey of monoelemental black phosphorus (BP) to BP-based composites plays a crucial role in expanding and advancing the development of BP in biological applications. Because of its exceptional unique structure and superior biological properties, BP has been extensively developed into various nanomaterials for different biological applications. However, the performance of BP alone cannot completely meet some specific requirements, and one possible route to harnessing its unique properties for different biological applications is to incorporate BP with a specific material to obtain an on-demand composite material. The manufacturing of such high-performance composites requires not only a full understanding of the structure and features of BP so that it could be perfectly incorporated with other materials or homogeneously distributed into various matrixes but also a clear biological effect of BP in different biological applications. Therefore, we summarize our recent work on BP-based high-performance composites for different biological applications, aiming to uncover (i) the evolutionary journey of BP from monoelemental materials to composite materials in biological applications and (ii) the interaction between BP and biological systems.Since the emergence of BP, BP-based materials have shown a prominent potential for technological applications as well as plenty of unexplored fundamental science. In particular, with the unlimited potential of BP in biological fields, it is desirable to take advantage of the useful performance of BP in composites through the combination of various functional materials for broadening its bioapplications. However, how to design and synthesize a BP-based composite with some specific performance remains a huge challenge due to the lack of an in-depth understanding of the interaction among BP, functional adjuvants, and physiological systems. BP-based nanosheets can selectively kill tumor cells via a reactive oxygen species (ROS)-mediated mechanism that indicates the biological effects of BP in physiological systems. Understanding the nanobio interaction of monoelemental BP materials can better make clear its fate in physiological systems, thereby contributing to the introduction of different functional adjuvants to decorate BP to obtain high-performance BP-based composite for different bioapplications. In addition, the functionalization or decoration of BP to form an additive-supported BP-based composite will further augment the performance of BP-based nanomaterials and broaden their bioapplication range. Owing to its high specific surface area and strong metal ion binding ability, BP nanosheets can serve as an ideal matrix to incorporate with small molecular drugs, metal ions, or metal nanostructures to obtain a multifunctional BP-based composite with enhanced properties for effective cancer therapy and photo/biocatalytic CO2 reduction. The combination of BP and the biomimetic matrix can also augment the performance of BP-based composites; therefore, fibrin gel with strong tissue healing could serve as an artificial skin to endow BP-based fibrin gel with excellent antibacterial ability, analgesia, and wound healing for diabetic ulcer therapy. Finally, we also outlook the future development and challenges as well as the clinical application prospect of an additive-supported BP-based composite.

A Review on Recent Advancements of Graphene and Graphene-Related Materials in Biological Applications

Graphene is the most outstanding material among the new nanostructured carbonaceous species discovered and produced. Graphene’s astonishing properties (i.e., electronic conductivity, mechanical robustness, large surface area) have led to a deep change in the material science field. In this review, after a brief overview of the main characteristics of graphene and related materials, we present an extensive overview of the most recent achievements in biological uses of graphene and related materials.

Atmospheric Corrosion, Antibacterial Properties, and Toxicity of Silver Nanoparticles Synthesized by Two Different Routes.

Silver nanoparticles (AgNPs) have been widely employed or incorporated into different materials in biological application, due to their antibacterial properties. Therefore, antimicrobial capacity and cytotoxicity have been highly studied. However, most of these reports do not consider the possible corrosion of the nanomaterials during their exposure to atmospheric conditions since AgNPs undergo a transformation when they come in contact with a particular environment. Derived from this, the functionality and properties of the nanoparticles could decrease noticeably. The most common silver corrosion process occurs by the interaction of AgNPs with sulfur species (H2S) present in the atmospheric air, forming a corrosion layer of silver sulfide around the AgNPs, thus inhibiting the release of the ions responsible for the antimicrobial activity. In this work, AgNPs were synthesized using two different methods: one of them was based on a plant extract (Brickellia cavanillesii), and the other one is the well-known method using sodium borohydride (NaBH4). Chemical stability, corrosion, antibacterial activity, and toxic activity were evaluated for both sets of prepared samples, before and after exposition to atmospheric air for three months. The structural characterization of the samples, in terms of crystallinity, chemical composition, and morphology, evidenced the formation of link structures with nanobridges of Ag2S for non- “green” AgNPs after the air exposition and the intact preservation of silver core for the “green” sample. The antibacterial activity showed a clear improvement in the antimicrobial properties of silver in relation to the “green” functionalization, particle size control, and size reduction, as well as the preservation of the properties after air exposition by the effective “green” protection. The cytotoxicity effect of the different AgNPs against mononuclear cells showed a notable increment in the cell viability by the “green” functionalization.

Functional Chitosan-based Materials for Biological Applications.

Bio-based materials, as the plentiful and renewable resources for natural constituents which are essential for biomedical and pharmaceutical applications, have not been exploited adequately yet. Chitosan is a naturally occurring polysaccharide obtained from chitin, which has recently attracted widespread attention owing to its excellent activity. This review shows the methods of extraction and modification of chitosan and provides recent progress of synthesis and use of chitosan-based materials in biological applications. By consulting the research literature of the last decade, the recent progresses of functional chitosan-based materials for biological applications were summarized and divided into the methods of extraction chitosan, the chemical modification of chitosan, chitosan-based materials for biological applications were described and discussed. Chemical modification of chitosan broadens its applications, leading to developing numerous forms of chitosan-based materials with excellent properties. The excellent bioactivity of chitosan-based material enables it serves potential applications in biomedical fields. Chitosan-based materials not only exhibit the excellent activities of chitosan but also show other appealing performance of combined materials, even give the good synergistic properties of chitosan and its composite materials. Further studies are needed to define the ideal physicochemical properties of chitosan for each type of biomedical applications. The development of various functional chitosan-based materials for biological applications will be an important field of research, and this kind of material has important commercial value.

Electrochemical quartz crystal microbalance with dissipation investigation of fibronectin adsorption dynamics driven by electrical stimulation onto a conducting and partially biodegradable copolymer.

Functional surface coatings are a key option for biomedical applications, from polymeric supports for tissue engineering to smart matrices for controlled drug delivery. Therefore, the synthesis of new materials for biological applications and developments is promising. Hence, biocompatible and stimuli-responsive polymers are interesting materials, especially when they present conductive properties. PEDOT-co-PDLLA graft copolymer exhibits physicochemical and mechanical characteristics required for biomedical purposes, associated with electroactive, biocompatible, and partially biodegradable properties. Herein, the study of fibronectin (FN) adsorption onto PEDOT-co-PDLLA carried out by an electrochemical quartz crystal microbalance with dissipation is reported. The amount of FN adsorbed onto PEDOT-co-PDLLA was higher than that adsorbed onto the Au surface, with a significant increase when electrical stimulation was applied (either at +0.5 or -0.125 V). Additionally, FN binds to the copolymer interface in an unfolded conformation, which can promote better NIH-3T3 fibroblast cell adhesion and later cell development.

Organic Room Temperature Phosphorescence Materials for Biomedical Applications

Organic room temperature phosphorescence (RTP) materials have drawn increasing attention due to unique features especially the long emission lifetime for applications in biomedicine. In this review, we will provide an overview of the recent developments of organic RTP materials applied in biomedicine field. First of all, we will introduce the basic mechanism of phosphorescence and various strategies of modulating the lifetime and efficiency of room temperature organic phosphorescence will be presented subsequently. Next, we summarized the progress of room temperature organic phosphorescence materials in biological applications, including bioimaging, anti-cancer and antibacterial therapies. Finally, the challenges and future perspectives in the field will be outlooked.

Fruit Biowaste Mediated Green Route Approach Silver Nanopartilces - As Antibacterial Material

Environmental free approach or green chemistry synthesis of metallic nanoparticles has become new growing branch of nanobiotehnology. In this present work a simple and environmental free biosynthesis silver nanoparticles (AgNPs) were prepared using Musambi Peels (MPs) aqueous extract as the reducing agent guided by the principles of green chemistry. The fruit waste aqueous extract was challenged with silver nitrate solution for the production of AgNPs in room temperature. The crystalline phase and morphology of AgNPs were determined from UV-Vis spectroscopy, Fourier transform infrared (FTIR) spectra, X-raydiffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS).The UV-Vis spectrum indicated that the surface plasmon broad peak was observed nearby 450 nm throughout the reaction 30min-24h. XRD spectrum revealed that the average size of biowaste mediated AgNPs obtained approximately 46 nm by using the Debye-Scherrer equation. SEM image of AgNPs showed uniformly distributed on the surface of the cell with high agglomeration. EDS analysis revealed that the presence of silver was confirmed from the Ag peaks at 2.8-3.7 keV. In addition, the biowaste mediated AgNPsloaded disk were tested for antibacterial properties against Escherchia coli and Staphylococcus aureus and found that the obtained metallic AgNPs have been good antibacterial material for biological applications.

Layered Double Hydroxides: A Toolbox for Chemistry and Biology

Layered double hydroxides (LDHs) are an emergent class of biocompatible inorganic lamellar nanomaterials that have attracted significant research interest owing to their high surface-to-volume ratio, the capability to accumulate specific molecules, and the timely release to targets. Their unique properties have been employed for applications in organic catalysis, photocatalysis, sensors, drug delivery, and cell biology. Given the widespread contemporary interest in these topics, time-to-time it urges to review the recent progresses. This review aims to summarize the most recent cutting-edge reports appearing in the last years. It firstly focuses on the application of LDHs as catalysts in relevant chemical reactions and as photocatalysts for organic molecule degradation, water splitting reaction, CO2 conversion, and reduction. Subsequently, the emerging role of these materials in biological applications is discussed, specifically focusing on their use as biosensors, DNA, RNA, and drug delivery, finally elucidating their suitability as contrast agents and for cellular differentiation. Concluding remarks and future prospects deal with future applications of LDHs, encouraging researches in better understanding the fundamental mechanisms involved in catalytic and photocatalytic processes, and the molecular pathways that are activated by the interaction of LDHs with cells in terms of both uptake mechanisms and nanotoxicology effects.

Supercritical CO2 assisted formation of composite membranes containing an amphiphilic fructose-based polymer

With the aim of increasing the mechanical and biological properties of different materials, a supercritical CO2 (SC-CO2) assisted technique was used to include a polymer with a natural origin (levan) in membranes of cellulose acetate (CA) and polyvinylidenefluoride-co-hexafluoropropylene (PVDF-HFP). CA-levan membranes were characterized by interconnected pores ranging from 9 to 13 μm; due to levan addition, composite membranes increased their mechanical resistance and cells adhesion (from 8% to 30%). In the second system, the processing of a PVDF-HFP-DMSO-levan colloidal suspension system caused a morphological modification and the generation of a foam-like structure; a decrease of the mechanical resistance and an increase of cells adhesion (from 8% to 35%) were observed. Stress-strain responses for both systems were fitted using two different hyperelastic equations, Yeoh and Ogden; deviations from experimental data lower than 15% were obtained.In conclusion, SC-CO2 assisted process was able to generate composite structures with levan, accessible to the cells; i.e., transforming polymers like CA and PVDF-HFP in potentially useful materials for biological applications.

The use of functionalized carbon xerogels in cells growth

In the present study carbon xerogels are used for the first time to study the fibroblast cell growth. For that, carbon xerogel microspheres are synthesized and thereafter functionalized with carbon nanofibers followed by the 1,3-dipolar cycloaddition of azomethine ylides (the so called “Prato reaction”) or the addition of aryl diazonium salts (the so called “Tour reaction”) to improve its wettability. The presence of nanofibers produces a huge improvement of the functionalization degree (59 versus 372 μmol/g for pristine carbon spheres and carbon spheres with 30% of carbon nanofibers, respectively) in spite of the blockage of the carbon spheres porosity caused after the nanofibers growth. This improvement was explained on the base of the increase of the number of probable active sites for the addition reactions (CC bonds) and the accessibility to these active sites (accessible surface area) by the presence of nanofibers. These high functionalization degrees reflect a promising potential of these materials in biomedical applications. Toxicity results obtained using a fibroblast cell line showed that samples are biocompatible for this kind of cells and that the presence of carbon fibers on the surface of the spheres increases the cells proliferation in a high extend reaching in some case values around 150% regarding the control. This study evidences that carbon aerogels could be interesting materials in biological applications, an unexplored field for this type of materials, being biocompatible, favouring the proliferation of cells and achieving high functionalization degrees.

Coumarin-Caged Polyphosphazenes with a Visible-Light Driven On-Demand Degradation.

Polymers that, upon photochemical activation with visible light, undergo rapid degradation to small molecules are described. Through functionalization of a polyphosphazene backbone with pendant coumarin groups sensitive to light, polymers which are stable in the dark could be prepared. Upon irradiation, cleavage of the coumarin moieties exposes carboxylic acid moieties along the polymer backbone. The subsequent macromolecular photoacid is found to catalyze the rapid hydrolytic degradation of the polyphosphazene backbone. Water-soluble and non-water-soluble polymers are reported, which due to their sensitivity toward light in the visible region could be significant as photocleavable materials in biological applications.

Promising effects of silver tungstate microcrystals on fibroblast human cells and three dimensional collagen matrix models: A novel non-cytotoxic material to fight oral disease

Silver tungstate (α-Ag2WO4) microcrystals have shown encouraging results regarding their antimicrobial activity. However, in addition to the promising outcomes in fighting oral disease, cytotoxic tests are mandatory for screening new materials for biological applications. Here, we developed a better understanding of the effects of microcrystals on the behavior of both human gingival fibroblast (HGF) cells and three-dimensional (3D) collagen matrices. To perform these experiments, the lowest concentration of α-Ag2WO4 capable of preventing the visible growth of Candida albicans (C. albicans) planktonic cells was defined as the test concentration, and it ranged from 0.781 (C1) to 7.81 (C2) to 78.1 (C3) μg/mL. Complete medium and lysis buffer (LB) served as negative (C-) and positive (C+) controls, respectively. The effect of the microcrystal concentration on the morphology, remodeling and proliferation of HGF cells was evaluated by different approaches. Quantitative and qualitative assessments demonstrated that α-Ag2WO4 did not affect the mitochondrial enzymatic activity of HGF cells cultured in a monolayer or the cell viability within 3D collagen matrices. These experiments showed that α-Ag2WO4 at the C2 concentration did not damage the genomic DNA. The development of new materials is attractive for the possible treatment of diseases and for avoiding indiscriminate prescribing of antibiotics. These findings provide information on the effect of α-Ag2WO4 on cell behavior and reveal that these microcrystals are non-cytotoxic against human gingival cells over a sufficient period to measure the hazard potential.

UV- and Thermo-Controllable Azobenzene-Decorated Polycarbodiimide Molecular Springs

Molecular switches offer wide applicability through conformational changes which can be triggered by external stimuli. Azobenzenes are excellent candidates to contribute toward a rational design of molecular switches because they exist as either cis or trans isomers as a result of the dynamic photoisomerization process. In this study, we leverage the azobenzene stimuli response by attaching it as a pendant group on polycarbodiimides synthesized using screw sense polymerization. The exposure of the polymer sample in solution to UV light induces the transformation of the azobenzene pendant groups to the cis isomer with re-emergence of the trans conformer under visible light or heat. Corroborating experimental and computational data reveal that these events induce spring-like expansion–contraction motions throughout the helical backbone. Our finding suggests the use of polycarbodiimide-derived photoswitches as dynamic materials in biological applications and materials science.